Biology of cicada killer wasps

wasp4


Eastern cicada killers (Sphecius speciosus) are the large wasps which dig burrows each summer in well-drained lawns, playing fields, plant nurseries and sloping terrain with varying amounts of grass east of the Rocky Mountains in the US and south into Mexico, Guatemala and Honduras. They begin their excavations a few weeks after our annual cicadas start singing. There are two related species, S. grandis, the western cicada killer, and S. convallis, the Pacific cicada killer, which are found in many US states west of the 94th meridian and Mexico and Central America. A fourth species, S. hogardii, the Caribbean cicada killer, is found in Florida, and the Caribbean nations and the spectacled cicada killer, S. spectabilis, is the only species in the genus reported from South America. Since little is known of the biology of the other four species, these pages present detailed information only on the eastern cicada killer.

The female cicada killer on the right is carrying a paralyzed annual cicada (Tibicen linnei) back to her burrow, where she will put it in a nest cell, lay an egg on it and seal the cell. A grub will hatch from the egg in a few days, eat the cicada and overwinter underground in a hard cocoon which it weaves. It will pupate in the spring, hatch in July or August, dig its way to the surface and live above ground for 2-6 weeks; all adults die annually. The cicada killer has adapted its life cycle to be in synchrony with that of its hosts: Like the several species of “annual” cicadas with which it feeds its young, a cicada killer spends over 90% of its life underground as a larva. Like most hunting and parasitic wasps, the cicada killer is a beneficial insect; it exerts a measure of biological control on cicadas, some species of which damage deciduous trees by laying eggs under the soft bark of the new growth on the trees’ terminal branches. Because they emerge each year in mid-July, cicada killers are not significant predators of periodical (13- and 17-year) cicadas, which emerge in May and June and die off by mid-July.

These illustrated pages are maintained as a resource for anyone interested in cicada killer biology. Please e-mail questions, comments or suggestions for further work to me at: hollidac@lafayette.edu Last updated 5/21/2012.

Have you caught a wasp that looks like the one on the right? If so, it’s not a cicada killer, but a European Hornet; click on the picture to go to Dieter Kosmeier’s excellent www page on these fascinating wasps.




fingerperch

Much more information about cicada killers:

Introduction: An overview of the cicada killer’s life cycle.

Biology of cicada killer males: Hangin’ tough on the lek and being there when the phone rings.

Mating: Unusual precopulatory behavior, complete with movies.

Biology of cicada killer females: Putting their eggs in different baskets and…..

Hunting: Making a tough choice for each egg – Will this one be a boy or a girl?

Larval development and hatching (more movies).

Cicada killer species, their distributions and a taxonomic key for the genus Sphecius in the western hemisphere (Holliday & Coelho, 2006).

Suggestions for cicada killer control. Thinking of using pesticides to control cicada killers on your property? You may want to think twice – pesticides only kill this year’s wasps and, if your property is attractive to them, cicada killers will likely return again next year.

More suggestions for control of cicada killers, on the excellent cicada killer page posted by my colleague, Prof. Joe Coelho, at Quincy University.

Publications and www sites dealing with cicada killers. All references made to the scientific literature on these pages are available at this link, which is also on Prof. Coelho’s cicada killer page.

Here’s a link to a commercial www page where you can buy T-shirts, mugs and lots of other things imprinted with a great picture of a cicada killer, and a link to a page of outstanding video clips of cicada killers and other digger wasps by Dick Walton.

Of course, there is an excellent entry on cicada killers in general in the Wikipedia, as well as one on the Eastern cicada killer in the USA.

help

The male cicada killer in the picture above perched on my finger when it was offered and used it to get a better view of the area it was watching for emerging, virgin females. Male wasps cannot sting, but they can, at least in theory, give a nasty bite with their large jaws, as can the females, which have even larger jaws.

The female wasp shown on the right tired while flying back to her burrow with a paralyzed cicada and had landed short of her goal. Still carrying her cicada, she accepted the offer of a “lift” from my hand, crawled up my arm, took off and flew the final 10 feet to her burrow.